A known section insulator, having insulation strips which are contact strips, is described in Fed. Rep. of Germany Pat. No. 30 45 258. While providing uniform contact properties, said known section insulator features high mechanical strength as well as a high degree of rigidity with a resulting high degree of torsional rigidity. This configuration prevents arc, in the immediate vicinity of the two insulation strips, which would damage the insulation strips. Thus, maximum service life and reliability are attained. Under adverse conditions, however, the fabric embedded in the plastic may adversely affect the creep resistance on the part of the contact surfaces of the insulation strips because of deposits such as carbon dust from the wear of the collector strips of the current collector.